DE102009003312A1 - Bonding device, ultrasonic transducer and bonding method - Google Patents

Abstract

The invention relates to a bonding device, in particular for the production of bonding connections between electrical conductors made of wire or strip material and contact points of substrates such as in particular of electrical circuits, wherein the bonding device has a bond head (2) rotatable about a, in particular vertical, geometric axis of rotation (D) on which a bonding tool (5) and an ultrasonic transducer (35) are provided for ultrasonic vibration excitation of the bonding tool (5). In order to further develop a bonding device of the type mentioned initially, it is proposed that the main extension direction (36) of the ultrasound transducer (35) and / or its extension direction in the direction of the axis of minimum moment of inertia be parallel to the geometric axis of rotation (D) of the bondhead (2). extends. In other aspects, the invention also relates to a bonding device or an ultrasonic transducer.

Description

The The present invention relates to a first aspect of a Bonding device, preferably for the production of bonds between electrical conductors made of wire or strip material and contact points of substrates such as in particular of electrical circuits, wherein the bonding device one around a, preferably vertical, geometric Rotary axis has rotatable bonding head, on which a bonding tool and an ultrasound transducer provided for ultrasonic vibration excitation of the bonding tool are.

such Bonding devices are known to work in such a way that means the bonding tool, in which it is in a common embodiment may be a so-called wedge, an area of an electric field to be bonded Ladder, for example. An aluminum or a gold wire, with a certain pressure force against a desired contact point of a Substrate, for example an electrical circuit, is pressed, while the bonding tool transverse to the direction of pressure ultrasonic vibrations carries and transfers to the conductor until a permanent so-called bond connection between conductor and contact point is made. For ultrasonic vibration excitation of the bonding tool serve so-called ultrasonic transducers (i.e. Vibration generator conventional Stack of disc-shaped Have piezo elements. To the piezo elements is conventionally in the way AC voltage applied that the piezo elements predominantly perpendicular to its disc plane and thus also the piezo element stack in their stacking direction alternating in time length expansions and upsetting. These periodic length changes rain conventional also the tool holder of the bonding tool to mechanical longitudinal vibrations in this direction of length changes at. As a tool holder becomes common an elongated in this same direction and conical tapered so-called horn used, at the top of the bonding tool used and, for example, held with a clamping screw so that it is with its tool longitudinal axis perpendicular to the transducer longitudinal axis, d. H. extends perpendicular to the direction of vibration. Consequently leads as well the tool tip an oscillating movement transverse to the tool longitudinal axis from, which is exploited for the preparation of the bond. Bond devices With such ultrasonic transducers offer numerous applications and benefits. On the other hand, there is often the need to work in a narrow Space to create numerous bonds, the so-called bondhead, d. H. the assembly of the bonding device to which the bonding tool and the ultrasonic transducer (and usually a so-called. Wire guide and at so-called. Dickdrahtbondern possibly a cutting tool) are attached, fast rotational movements around a vertically oriented geometric Execute the rotation axis got to. It is considered restrictive Consider that one with a conventional ultrasonic transducer stocked Bond head functional and thus design a large moment of inertia has, which impedes the Bondkopfdrehung or to large rotary actuators forces.

In front In this background, the invention is first based on the object, develop a bonding device of the type mentioned advantageous, so that in particular the aforementioned disadvantages possible be largely avoided.

The Task is according to the invention first and essentially solved in conjunction with the feature that the main extension direction of the ultrasonic transducer and / or Its extension direction in the direction of the geometric axis of the minimum mass moment of inertia parallel (with or without lateral spacing) to the geometric Rotary axis of the bonding head extends. In the said main extension direction it is the extension direction of the ultrasonic transducer, in which he the largest dimensions when comparing its extension directions having. Also with the mentioned axis of rotation of the bondhead acts it is primary around a geometric, d. H. not necessarily a structural axis. By the chosen one solution is achieved according to the invention, that the moment of inertia around the geometric Bondkopfdrehachse compared to conventional Bonding devices, in which the main extension direction of the ultrasonic transducer perpendicular to the geometric axis of rotation of the bonding head is reduced. Let that way faster rotations of the bondhead around its vertical geometric Reach or only be comparatively for the rotary actuator smaller drives needed.

According to one second aspect, the present invention relates to an ultrasonic transducer, especially for a bonding device for ultrasonic vibration excitation of the bonding tool of Bonding device, wherein the ultrasonic transducer at least one Vibration generator comprises and the vibration exciter at least a piezoelectric element and wherein an ultrasonic energy source, in particular a voltage source for applying alternating electrical voltage to the piezoelectric element, is provided.

Based on the state of the art explained in the introduction, the invention is based on the object of further developing such an ultrasonic transducer so that can be achieved in particular manufacturing technology and / or technical benefits.

These Task is according to the invention first and solved essentially and in conjunction with the features that the ultrasonic energy source, in particular the voltage source, preferably their frequency, in particular voltage frequency, adapted thereto or is adjustable so that in operation, in particular when applying the AC voltage, the main deformation direction of the vibration generator and / or the main deformation direction of Piezoelementes transverse or perpendicular to the polarization direction of the Piezoelectric element extends. This is a basic one Departure from conventional Transducer versions, in which the main deformation direction of the vibration exciter (for example, a Stack of piezoelectric element disks) or the main deformation direction the piezo elements themselves parallel to the polarization direction of Piezo elements is located. Under the main deformation direction is the Understood spatial direction in which the compared to other directions largest deformations (ie compressions and strains) according to the applied electrical AC voltage can be caused. In the polarization direction it is a dedicated to the piezo element, in a certain Directional orientation in the production of piezoelectric elements is impressed by alignment of dipoles in an electric field and after the production remains largely (so-called. remanent polarization). When applying an AC voltage to the Piezoelement undergoes this generally alternating upsets and strains in all Spatial directions, whereby the respective extent or the amount in the different Spaces in general varies differently. The Invention is based on the recognition that there are certain AC frequencies exist in a respective individual assigned spatial direction (or geometric body axis) at one compared to the rest Spatial direction amount greater change in length to lead, these frequencies are also dependent on the shape and dimensions of the piezoelectric element and under circumstances the adjacent or resonant components are. According to the invention through the proposed solution in particular when using disk-shaped or thin piezoelements, whose polarization direction is perpendicular or transverse to the disk plane extends, for a given voltage comparatively high field strengths and thereby high transferable by the changes in shape personnel produce. Added to this is the advantage that more freedom in the design is obtained by transducers and a simple assembly of the piezo elements allows becomes. The invention concludes in this respect also a bonding device, preferably for the production of Bond connections between electrical conductors made of wire or strip material and contact points of substrates such as preferably of electrical circuits, with a bonding head having a bonding tool and a Ultrasonic Transducer according to the preceding described embodiment having.

According to one Third aspect, the invention relates to an ultrasonic transducer for ultrasonic vibration excitation a bonding tool, wherein the ultrasonic transducer at least two spaced from each other on a tool holder attacking vibration exciter and wherein at least one ultrasonic energy source for supply the vibration exciter, in particular at least one voltage source for applying electrical alternating voltage to the vibration exciter, is provided.

From that Based on the object of the invention, an advantageous To provide development of such a bonding device.

According to the invention, the object is achieved initially and essentially in conjunction with the features that one or more ultrasonic energy sources, in particular the voltage source or the voltage sources, preferably the frequency and / or the phase position, for example, the AC voltage or AC voltages generated thereof, in the manner of the structure the oscillation exciter is tuned or tunable to the fact that in operation, especially with applied AC voltage, the main deformation directions of the two oscillators parallel or substantially parallel to each other and the time-varying deformation of the two oscillators phase-shifted, preferably by half a period, ie 180 ° out of phase, expire or result. The term period is used here instead of or equivalently for the term phase length, and a phase shift of 180 ° (opposite phase) would be present at a phase shift by half the phase length. With regard to the third aspect, the invention also encompasses a bonding device, preferably for producing bonded connections between electrical conductors made of wire or strip material and contact points of substrates, such as preferably electrical circuits, wherein the bonding device has a bonding head to which a bonding tool received in a tool receptacle , which is preferably a wedge, and the above-described ultrasonic transducer according to the invention are provided. By a plurality of, preferably two, spaced from each other on the tool holder engaging piezoelectric elements have different time deformation profiles, the tool holder performs an oscillating rotation movement and transmits them to the received therein end of the preferably elongated bonding tool. Due to the periodically changing angle of rotation of the tool holder or by the oscillating torque introduced thereby into the bonding tool, the bonding tool is excited to transverse oscillations, ie to oscillations perpendicularly or transversely to its longitudinal extension or main extension direction. This oscillation, which is also referred to as flexural vibration or transverse vibration, is, unlike the prior art, not excited at the location of a so-called antinode, but preferably at the location of a so-called oscillation node of the frequency-dependent oscillation mode (also oscillation mode). The transverse vibration detects the entire bonding tool and, with a suitable design or design of the bonding tool, also causes its tool tip to execute vibrations transversely to the tool longitudinal direction which can be transmitted to an electrical conductor for producing a bond connection by pressing on the bonding tool.

It It is understood that in the context of the present invention, combinations the solution characteristics of two or all of the three previously explained Invention aspects possible are. As piezo elements can in principle all for Piezo actuators known piezoelectric element types are used, wherein the use of piezoelectric ceramics or piezoelectric Crystals is preferred.

Especially in connection with the first aspect of the invention is preferred that the geometric longitudinal center line of the ultrasonic transducer parallel to the geometric axis of rotation the bondhead and / or parallel to the longitudinal centerline of the bonding tool extends. In this way, the mass moment of inertia about the bondhead axis of rotation be minimized. There is also the possibility that the ultrasound transducer at least one vibration exciter, preferably two to each other parallel vibration exciter, comprising, each vibration exciter at least one piezo element, preferably in each case two piezo elements, wherein each piezoelectric element has a main extension direction has, which extends parallel to the geometric axis of rotation of the bonding head. The term main extension direction means that the dimension of the piezoelectric element in this direction larger than in other directions is.

Especially in conjunction with the second aspect of the invention preferred that the ultrasonic energy sources, in particular the voltage source, preferably their voltage frequency, adjusted or so adjustable is that when concerns the AC voltage, the main deformation direction of the vibration generator and / or the main deformation direction of or the piezoelectric elements in the main direction of extension of or the piezo elements extends.

Especially in connection with the third aspect of the invention is preferred that the design of the means of the ultrasonic transducer to oscillate excitable components of the bonding head and the AC voltage, in particular whose frequency are so coordinated or tunable, that the fulcrum and in particular the instantaneous pole of the tool holder in position on one Vibration node of the bonding tool is located.

Regarding The above aspects of the invention also provide the possibility that the frequency at the ultrasonic energy source, preferably the Voltage frequency at the voltage source, so preselected or is adjustable to be a resonant frequency the lowest or first resonance frequency, d. H. the first eigenmode, the oscillating at applied AC voltage assembly, the the ultrasonic transducer, the tool holder and the tool includes, exactly or roughly corresponds. Preferably, the oscillatory System with the bonding tool in its first natural frequency and thus excited in its associated first eigenform to vibrate be, it would be but also a vibration excitation for example, second, third, etc. natural frequency / eigenform possible. An expedient embodiment is seen in that one or more piezo elements each has or have the shape of a rectangular bordered disc, where the edge lengths the rectangular contour is larger than the thickness of the disk are and where the polarization direction of each Piezoelementes with respect to its disc plane transversely or vertically is oriented to it.

To initiate an oscillating torque in the tool holder or in the bonding tool is preferred that the ultrasonic transducer has at least two mutually parallel vibration exciters, each vibration exciter has a piezoelectric element and two similar piezoelectric elements facing away from each other on two opposite gegenü and lying to each other attached to parallel surfaces of the piezoelectric element carrier, preferably glued thereto flat, are. As a result, and in conjunction with the selected AC voltage frequency, it can be achieved that practically only the change in length of the piezoelectric elements in their main extension direction is used for the vibration excitation of the bonding tool. Due to the planar attachment of the piezoelectric elements and the piezoelectric carrier element, the preferably made of metal such as. Steel or titanium may consist, deformed accordingly. Each vibration exciter thus has a sandwich-like arrangement of a central piezoelectric element carrier between two opposite piezoelectric elements. In connection therewith and the said parallel arrangement of two such vibration exciters, it is preferred that the polarization direction of piezoelectric elements which are part of the same vibration exciter be directionally opposite to one another in directional terms, that is to say have quasi opposite signs. In connection therewith, it is also preferred that the polarization directions of the two piezo elements, which are applied to one of the two piezoelectric element carriers, are directionally orthogonal away from the surface of the piezoelectric element carrier, and that the polarization directions of the two piezoelectric elements applied to the other of the two piezoelectric element carriers are directionally orthogonal to the surface of the Piezoelementträgers executed. With the aforementioned features, the desired different and in particular opposite changes in length of the two vibration exciters can be realized particularly simple circuit technology by applying the same or the same, ie in-phase, AC voltage to all the piezo elements and the piezo element carriers are grounded, for example. In particular, there is the possibility that the piezoelectric elements are simply connected, for example, on their free surface remote from the piezoelectric element carrier by means of soldering points to the ultrasonic energy source, in particular to the voltage source. It is thus possible to use an ultrasound energy source or voltage source which provides only a single AC voltage, for example, the form u (t) = Ucos (ωt), which is applied to all the piezo elements, for example by the connecting lines of all the piezo elements being connected in parallel to one another. A possible arrangement which is advantageous with regard to the previously described mode of action is seen in that the geometric longitudinal axis of the bonding tool extends parallel to the main extension direction of the piezoelements and / or along the geometric axis of rotation of the bondhead. In a preferred space-saving and stable embodiment, it is provided that two piezoelectric element carriers are provided, which are components of a common one-piece transducer body, on which preferably also the tool holder for holding the bonding tool is formed in one piece. In this sense, it is also preferred that the transducer body integrally or integrally comprises a holding fork, the holding arms of which engage at their longitudinal end on a respective piezoelectric element carrier in its longitudinal central region.

The The invention also relates to an ultrasonic transducer comprising at least one transducer body and at least one vibration excitation element connected to the transducer body in one for transmission the vibrations it generates on the transducer body Way, and beats to the advantageous development that the ultrasonic transducer, preferably with a bonding tool mounted on its tool holder, has a vibration mode whose waveform in the mounting point of the bonding tool a rotationally oscillating movement about at least causes a rotation axis. A preferred development is seen in that the vibration excitation element on the transducer body frictionally and / or positive fit and / or cohesively is attached. It is also preferred that the oscillatory rotational Movement about at least one to the longitudinal axis the bonding tool perpendicular or at least substantially vertical imaginary or geometric axis of rotation is oriented. In further Particular there is the possibility that by the geometric longitudinal axis of Bondwerkzeuges or a parallel geometric line and through said axis of rotation an imaginary or geometric reference plane is spanned, that the at least one vibration excitation element is arranged laterally spaced from the reference plane and that the force exerted by the vibration excitation element on the transducer body force in or substantially in the direction of or parallel to the (intended to be elongated) longitudinal axis the bonding tool acts. It is considered appropriate that at least two laterally spaced from the reference plane vibration excitation elements are present, with respect to the reference plane opposite each other are arranged. Another possible Embodiment provides that one or more ultrasonic energy sources, preferably one or more voltage or current sources provided are for powering the vibration excitation elements, the are connected to the vibration excitation elements such that this one to each other by 180 ° out of phase Exercise vibration.

In a preferred embodiment it is provided that on each side of the reference plane at least two vibration excitation elements are arranged, arranged on both or different sides of the reference plane arranged vibration excitation elements in pairs, wherein on the same side of the reference plane to each other adjacent vibration excitation elements with the one or more energy sources are connected to exert mutually 180 ° out of phase oscillations, and wherein pairwise with respect to the reference plane opposite vibration excitation elements are connected to the one or more ultrasonic energy sources such that they mutually 180 ° phase-shifted vibrations ausü ben. A compact design, which is advantageous in particular with regard to the lowest possible moment of inertia about the longitudinal axis of the tool is achieved in that each at least two arranged on the same side of the reference plane Schwingungserre transmission elements are arranged in the direction of the geometric longitudinal axis of the bonding tool behind the other. There is the possibility here that the transducer body comprises only one vibration excitation element carrier and that the vibration excitation elements, preferably all vibration excitation elements, are arranged to form only a single vibration exciter on two opposite, mutually remote surfaces of the vibration excitation element carrier, wherein the vibration excitation element carrier at least substantially the shape of a rectangular Cuboid or a rectangular plate possesses. In principle, such an ultrasound transducer differs structurally from the ultrasound transducer described above with two vibration exciters arranged parallel to one another, but also makes it possible to introduce an oscillating torque into the bonding tool at its tool holder. In one embodiment, it is provided that at least one piezo element is provided as the vibration excitation elements, so that the transducer body comprises only one, all piezo elements supporting piezoelectric element carrier which has at least substantially the shape of a rectangular cuboid or a rectangular plate.

Out the previous versions It will be apparent that the bonding devices proposed by the invention and their ultrasonic transducer substantially from the previously known Different designs. Known, in ultrasonic welding usually used transducers are from a vibrator to longitudinal vibrations stimulated, transmitted this at a perpendicular to the direction of vibration tool and stimulate this to bending vibrations. In contrast, the present invention aims to a new arrangement in which the orthogonal orientation of the Tool to the transducer is no longer necessary. Regarding of the moment of inertia and the construction volume can thus achieve an improved design become. Also can be by the use of simple Kör by (z. B. plates, discs simple contour) the manufacturing cost of the transducer reduce and the installation of actuators or vibration excitation elements simplify on the transducer. According to the already described Aspects suggests the invention that the main extension direction, ie the directions the axis of minimum moment of inertia of the transducer, and the tool are identical. The transducer is caused by vibration exciters or vibration excitation elements excited to oscillate, so that for the operating frequency a Vibration forms at the attachment point of the tool performs a substantially rotational movement and thereby the tool excites in a node of its waveform to bending vibrations. When a possibility beats the invention in that the transducer or Transducererkörper in essentially of two coupled areas of a preferably disc-shaped body any Contour and possibly changeable (in particular in the direction of extension stepped) thickness and by means of vibration exciters or vibration excitation elements to longitudinal vibrations is excited, wherein the tool vibrates in the plane of the disc-shaped body. Preferably, at least two actuators (vibration excitation elements) flat in the left or right area on opposite outer surfaces of the transducer, which run parallel to the main extension direction, mounted. A preferred installation is, for example, the sticking of the actuators, basically come here but alternatively or combinative non-positive, positive and cohesive Compounds considered. The control of opposing actuators is preferred phase. In one possible Variant, at least four actuators (vibration excitation elements) flat on two opposite each other Outside surfaces of the two coupled areas parallel to the main extension direction run, mounted. Within a range are the actuators again preferably driven in phase, while the two areas in opposite phase be driven (phase is preferably 180 °).

in the Regarding the orientation of the main extension direction and the described design is in this solution by a vertical transducer to speak, which has two coupled areas.

According to another solution, which has already been described, the invention provides that the transducer is made to vibrate from a plate-shaped body which is vibrated by the vibration generator (s) or by vibration excitation elements mounted on two opposite outer surfaces parallel to the longitudinal axis of the transducer. The tool vibrates, in contrast to the previously described transducer formed from two coupled part bodies, perpendicular to the plane of the plate-shaped body. It is possible to mount on the outer surfaces in the upper half of the body, two actuators (vibration excitation elements) and to control these in phase opposition. An alternative is that four actuators (vibration excitation elements) are mounted on the transducer, especially two actuators on each side, and one each in the above and in the lower half. The lying on one side actuators are preferably driven in phase opposition. It follows that each diagonally opposite actuators are driven in phase with each other. Regarding these variants, there is a one-piece vertical transducer in terms of orientation and design.

The Invention finally offers also the possibility combinations of the vertical transducer with two coupled Areas and the one-piece Vertikaltransducer. These lead that the bonding tool in the mounting plane not only on one Straight lines, but also can swing on a circular path and / or a further component of motion perpendicular to the mounting plane receives.

The Invention also relates to a method for the production of bonds, preferably, d. H. not necessary (for example, could be synonymous plastic parts or connect other ultrasonically weldable components), between electrical conductors made of wire or strip material and contact points of substrates, such as electrical circuits, comprising the following steps: providing a Bonding tool, providing an ultrasonic transducer to Ultrasonic vibration excitation of the bonding tool, wherein the ultrasonic transducer includes at least one vibration exciter and the vibration exciter has at least one piezoelectric element, providing an ultrasonic energy source for supplying the piezoelectric element, preferably a voltage source for applying electrical alternating voltage to the piezo element, and vibration excitation of the bonding tool during pressing of a to be bonded electrical conductor by means of the bonding tool a contact point.

Under Reference to the above statements is the invention insofar the task is based, such a bonding method advantageous further education.

The Task is according to the invention first and essentially solved in conjunction with the features that for the Vibration excitation of the bonding tool the ultrasonic energy source, preferably the voltage source, preferably its ultrasonic frequency, so chosen or is set that in operation, preferably when creating the AC voltage, the main deformation direction of the vibration generator and / or the main deformation direction of the piezoelectric element transverse to the polarization direction of the piezoelectric element extends. For related effects and benefits is concerned with the invention in particular the second aspect previous versions Referenced.

The Invention also relates to a method for the production of bonds, preferably between electrical conductors made of wire or strip material and contact points of substrates, such as electrical Circuits comprising the following steps: providing a Bonding tool and an ultrasonic transducer for ultrasonic vibration excitation of the bonding tool and vibration excitation of the bonding tool during the press an electrical conductor to be bonded by means of the bonding tool to a contact point.

to advantageous development of such a method proposes the invention vor that in the bonding tool to its vibration excitation at the Tool holder an oscillating torque is introduced, wherein the geometric axis of rotation of the torque transverse to the tool longitudinal axis runs. For holding the bonding tool on the bonding device or on the bonding head preferably engages the tool holder at the top End of the bonding tool on. For possible effects and advantages is based on the preceding, in particular the third aspect of the invention relevant statements Referenced. The method can preferably be carried out in such a way that the oscillating torque at the location of a vibration node the bonding tool is introduced therein.

Nice from the previous versions shows that to power the vibrator or the Although preferably, but not necessarily a voltage source to choose is. Rather, as an energy source for generating the ultrasonic vibrations (i.e., as an ultrasonic energy source) instead, for example one or more power sources or other types of energy sources serve (for example, a magnetic energy source). As part of the various Aspects of the invention refers to the term vibration exciter generally a carrier with at least one vibration excitation element attached thereto, d. H. with at least one actuator, the actuator in general a piezoelectric operation (in an embodiment as Piezo element) or have a magnetostrictive mode of operation can.

The said method according to the invention can preferably using an ultrasonic transducer or a bonding device executed whichever or whichever or several of the foregoing and / or features described below.

The Invention will be described below with reference to the attached figures, which preferred embodiments of the invention show in more detail described. It shows:

1 the bonding head of a bonding device according to the invention according to a preferred embodiment in a side view;

2 in perspective and in contrast in magnification in the arrangement of 1 included ultrasound transducer;

3 a side view of the ultrasonic transducer in the direction of III according to 2 ;

4 an enlarged sectional view of the ultrasonic transducer along section line IV-IV according to 3 ;

5 in perspective, the transducer body of the in 2 illustrated ultrasound transducer;

6 a section at the bottom partially sectioned side view of the Transducer body in the direction of VI according to 5 ;

7 one of the 3 comparable side view, which exemplarily and schematically simplified areas of piezo elements are designated with different degrees of deformation;

8th one too 1 alternative embodiment of a preferred mounting of the ultrasonic transducer for Bondkopfbefestigung;

9 perspective view of an inventive ultrasonic transducer with inserted therein bonding tool according to another preferred embodiment;

10a a sectional view taken along the sectional plane Xa in 9 , in contrast, a little smaller and

10b the sectional view according to 10a , wherein by means of a dashed wavy line schematically a momentarily occurring waveform is entered.

With reference to the 1 to 6 First, a preferred embodiment of a bonding device according to the invention and a method according to the invention for the production of bonding compounds will be described, wherein 1 the bonding device 1 only in the area of its bondhead 2 shows and the 2 to 6 enlarged views of components of the bondhead 2 play. The bondhead 2 is at the bottom of one at the bonding device 1 in a manner not shown about the vertically extending axis of rotation D rotatably held wheel 3 attached. In order to effect a rotation, in the embodiment, a partially shown toothed belt 4 which is in an external toothing of the wheel 3 engages to be moved by means of a non-illustrated with him, driven by him driven wheel to a desired depending on the rotation distance. In addition, drives can be provided to the entire bondhead 2 to move laterally in different directions of a plane perpendicular to the axis of rotation D level. The bondhead 2 has an elongate, along a central tool longitudinal axis W extending bonding tool 5 on. At the upper longitudinal end of this is in a tool holder 6 with its shaft in a likewise vertical, diameter-corresponding bore 7 (see. 6 ) and therein by means of a clamping screw 8th held tight. At the lower longitudinal end of the bonding tool 5 is a tool tip 9 formed, with the lower end in a conventional manner, an electrical conductor to be bonded, for example. From wire or strip material, against a provided for the bonding connection pad of a substrate, preferably a contact of a circuit can be pressed. In order to supply the bonding point with a wire-shaped or ribbon-shaped conductor, the bonding device has a wire guiding device 10 , at the lower end of which a laterally open guide groove 11 located. In order to hold the electrical conductor during bonding at certain times and be able to exert a pulling action on it, the bonding device has a clamping device 12 with two facing each other in the direction of 1 overlapping clamp legs 13 whose free ends are between the tool tip 9 and the lower end of the wire guide device 10 are located. On the known function of Drahtführungs- and the clamping device does not need to be discussed here. Both components are adjustable in position and can be in the desired position by suitable means with respect to the wheel 3 or an attached rigid support arm 14 be fixed. The tool holder 6 is in one piece at the bottom of one in the 5 and 6 individually illustrated transducer body 15 formed. The overall disc-like, made of an electrically conductive material (eg. Made of steel) transducer body 15 Incidentally, in each case comprises two each rectangular-edged piezoelectric element carrier 16 whose main directions of extension 17 parallel to the geometric Drehach se D and the coincident or only slightly spaced tool axis W run. In each case in the region of the approximately middle lower edge of each piezoelectric element carrier is a connecting web 18 from, with its respective lower end, the two piezoelectric element carrier 16 spaced apart laterally (ie, spaced apart from each other transversely to the direction of rotation D) at the top of the tool holder 6 attack. Furthermore, the transducer body comprises 15 a holding fork 19 for holding the piezoelectric element carrier 16 at the bondhead 2 , For this purpose, hold arms 20 the holding fork 19 at its lower longitudinal end 21 on each a piezoelectric element carrier 16 in whose longitudinal center area (relative to the extent or dimensions in the main extension direction 17 ) in one piece. At the same height are in their main extension direction 17 parallel extending piezoelectric element carrier 16 by means of a material bridge 22 connected. Otherwise, the two piezo element carriers 16 as shown from each other through narrow slots 23 . 24 and from the holding fork 19 through narrow slits 25 . 26 spaced. In its upper part, the holding fork 19 Through holes 27 by means of which the transducer body 15 by means of screws 28 stuck to a plate 29 is mounted. The plate 29 in turn is with screws 30 on a frame section 31 screwed on, like the arm 20 Part of one at the bottom of the wheel 3 fixed mounting frame 32 is. In 1 is this frame, as far as it is covered by other components, shown in dashed lines. Insofar recognizable owns the mounting frame 32 four reduced in cross-section sections 33 , which have a relatively lower rigidity and serve as a solid body joints due to their flexibility. The in the direction of 1 left edge of the mounting frame 32 is like the holding arm 20 rigid on the wheel 3 attached, while the right in the direction of the frame section 31 According to the solid state joints by means of an actuator not shown on the frame section 34 exercisable force F can be deflected relative to this by a certain distance down to, for example, the bonding tool 5 Press from top to bottom on the bond. When the force F is released, the frame section returns 31 elastic return to its rest position.

The 2 to 4 show the transducer body 15 as part of the bonding head 1 existing ultrasound transducer 35 , in its tool holder 6 again the bonding tool 5 is used. For example. from the 1 and 3 shows that the main extension direction 36 of the ultrasound transducer 35 runs parallel to the geometric axis of rotation D of the bonding head, which coincides with the tool longitudinal axis W of the bonding tool or can run at only a small distance therefrom. Due to the chosen in the example, substantially side-symmetrical structure of the ultrasonic transducer 35 Its longitudinal symmetry line S with the geometric axes D and W also drops to only a small lateral offset (see ΔX in FIG 3 ) together. The in the 2 to 4 magnified ultrasound transducers 35 has two adjacent, mutually parallel vibration exciters 37 on. Every vibration exciter 37 includes one of the two piezo element carrier 16 and two disc-like, in their main plane of extension (see. 3 ) rectangular bounded piezoelectric elements 38 of which the two respective piezoelectric elements belonging to a vibration exciter surface on the two opposing opposite and mutually parallel surfaces 39 . 40 of the relevant piezoelectric element carrier 16 are adhered flat over the entire contact surface. The 2 and 3 show that in this contact level (ie parallel to the drawing plane of 3 ) the boundary or the shape of the Piezoelementträger 16 and the piezo elements adhered thereon 38 is identical, with a so far precisely fitting or aligned bonding is present. As a result, also the main extension direction 41 the piezo elements 38 parallel to the geometric axis of rotation D of the bondhead 2 runs. For the selected piezo elements 38 is to speak of a disc-like shape, since its dimensions in the plane parallel to the plane of 3 lying main plane of extent greater than the thickness in the perpendicular and parallel to the plane of 4 extending level. In 4 are also indicated by arrows, which are denoted by the reference symbol P, the polarization directions of the four piezo elements 38 specified. Visible extends the polarization direction P of each piezoelectric element 38 perpendicular to its disk plane. It is also shown that in each case a pair of piezo elements 38 belonging to the same vibration exciter, the polarization directions are directionally opposed to each other. In more detail, in the in 4 embodiment shown, the polarization directions P of the piezoelectric elements 38 of the left-hand directional vibration exciter 37 perpendicular from the contact surfaces 39 . 40 away, ie to the outside. Deviating from this, the polarization directions P of the piezo elements 38 of the lying in the direction of the right vibration generator 37 each perpendicular to the respective contact surface 39 . 40 towards, ie inside. The ultrasound transducer 35 is in the example shown to a voltage source 42 connected by two outgoing, parallel to each other electrical conductor 43 at their ends by means of solder joints 44 at two each other on the same (in 4 right) Piezoelementträger 16 opposite piezo elements 38 are attached. This in 4 symbol used indicates that it is the voltage source 42 is an AC source. Alternatively, a different ultrasonic energy source (ie, energy source for generating ultrasound), such as an AC source, could be used. By means of further electrical conductors 45 and their solder joints 44 become pairs of piezo elements 38 , which are glued within the same level on the adjacent piezoelectric element carrier, electrically conductively connected. Furthermore, in the example chosen here, the respective adhesive bond between the piezo elements 38 and the piezoelectric element carriers 16 electrically conductive executed, but instead would be an electric non-conductive adhesive bond possible. The piezo element carriers 16 are as with the reference numerals 46 marked, each (or jointly) grounded. This is due to the four piezo elements 38 perpendicular to its disc plane in each case in terms of magnitude and phase the same AC voltage when the voltage source 42 is turned on.

While 3 the ultrasound transducer 35 and the bonding tool mounted therein 5 with the voltage source switched off 42 shows, gives 7 for comparison schematically simplified and exemplified the for a given time when the power source is switched on, ie when applying an electrical alternating voltage with an example selected for the calculations frequency and amplitude, occurring due to the piezoelectric effect deformations of the vibration exciter 37 , the tool holder 6 and the bonding tool 5 again. The low, even in the area of the retaining fork 19 occurring deformations are not shown for simplicity. Shown is the overall deformation of a so-called. Main mode, wherein the surface of the piezoelectric elements 38 for the purpose of calculation in fields bordered by grids 47 was divided. The diagram shows that the relative positional deviation along an approximately central belt, the longitudinal ends 21 the two retaining arms 20 connects, is the smallest and at the two longitudinal ends of the piezoelectric elements is greatest. When comparing with 3 is clearly visible that the lying in the direction of the left piezoelectric elements 18 with the piezoelectric element carrier in between, ie the left-hand oscillation exciter in the viewing direction 37 , by the applied AC voltage at the time considered compared to the dead state (see 3 ) a compression or length reduction in the associated main extension direction 17 respectively. 41 experiences, while the right adjacent vibration exciter 37 including its two piezo elements 38 and the piezoelectric element carrier 16 , at this time undergoes a length increase in this direction. Despite the same at all times piezoelectric elements at the same voltage, the two couples perform oscillations due to the different polarization as described directions, by half a phase length shifted deformation oscillations. The numerical values assigned to the different hatches give as comparison values the respective relative positional deviation of the regions from the de-energized state of 3 at. Due to the opposite changes in length of the two parallel vibration exciter 37 becomes the tool holder 6 , starting from the de-energized resting state in 3 , Raised at its left longitudinal end and lowered at its right longitudinal end, so that around the pivot point P _M, a rotation in the direction of the arrow 48 results. The pivot point P _M is located at the upper, clamped in the tool holder longitudinal end of the bonding tool 5 , wherein the geometric axis of rotation of the rotation through the point P _M perpendicular to the plane of 7 and thus also perpendicular to the longitudinal course of bonding tool 5 extends. Although on all four piezo elements 38 the same voltage is applied to the two vibration exciters 37 achieved the desired mutually opposite change in length, since the polarization direction P of the piezo elements 38 between the two vibration exciters 37 are oriented inversely. Since the magnitude and sign of the alternating voltage, the frequency of which is in the ultrasonic range, ie the instantaneous value, are constantly changing, this also has length changes of the vibration exciter, which occur with the appropriate frequency 37 result, among other things, at certain times both vibration exciters 37 have the same length and, among other things at still other times to 7 opposite aspect ratios occur. This causes the tool holder 6 is excited to oscillating rotational movements about the leading axis through the point P _M axis of rotation, so that at the point P _M in the bonding tool 5 an oscillating torque M is initiated. In this way, the bonding tool 5 , as in 7 shown excited to a bending vibration. For comparison, in 7 also the in 3 contained, ie the dead center state concerned tool longitudinal axis W entered. The center point P of the rotational movement lies on this reference line W, ie represents a so-called vibration node of the eigenform. Deviating from this, the tool tip 9 a significant lateral deflection perpendicular to the reference line, ie located on a so-called. Schwingungsbauch. In the course of the running oscillation cycles, the tool tip moves 9 substantially perpendicular to the tool longitudinal axis W. When pressing an electrical conductor to be bonded to a substrate (not shown) by means of the tool tip 9 As a result, the conductor is also caused to oscillate relative to the substrate, whereby the bond connection is produced.

In the in the 3 and 7 The embodiment shown is the voltage source 42 (in the 7 is not shown for clarity) with respect to the generated AC voltage and their voltage frequency so tuned to the entire oscillating system that when applying the AC voltage, the geometric deformation lines 49 of the two vibration exciters 37 representing the main geometric deformation lines 50 the piezo elements 38 correspond, transverse to the polarization direction P of the piezo elements 38 extend. The geometric main deformation lines 49 . 50 Significantly correspond to the premise chenunabhängigen main deformation direction. In 7 is the perpendicular to the plane through the point P _M leading axis of rotation with A and that about this axis of rotation A in the bonding tool 5 introduced torque designated by the reference symbol M.

8th shows in the form of a predominantly sectioned side view of the illustrated ultrasonic transducer 35 in conjunction with one of 1 deviating designed mounting frame 32 , This can by means of his only indicated screwing 51 preferably at the in 1 shown wheel 3 be attached, ie can in the in 1 Bonding head shown instead of the mounting frame shown there 32 be used. At the ends facing each other 52 of the lower cross member 53 grips the mounting frame 32 on each a piezoelectric element carrier 16 at. This connection can be made either integrally or in one piece or in several parts (for example by gluing, screwing or the like) in any desired manner. In the preferred case, that the connections to the with 52 designated bodies are made in one piece, it is the combination of Transducererkörper 15 and frame 32 around a single component. Starting from the illustration in 8th Would then be the hatching in the region of the piezo element carrier 16 according to the hatching of the frame 32 to choose. The attack takes place in each case in a medium length range of the vibration exciter 37 at the level of the material bridge 22 so that too on a separate holding fork 19 (see. 1 ) can be omitted. In the lower crossbar 53 are each adjacent to the ultrasound transducer 35 and to the vertical beams 54 pairwise sections 33 provided with reduced frame cross-section, which act as solid-state joints. In this way, a particular even one-piece transducer parallelogram is formed, which provides a certain elastic lowering of the bonding tool 5 by means of a downward pressure force F allows. The pressing force F can, for example, as in 8th shown on the material bridge 22 or attack elsewhere on the transducer.

In the 9 and 10a . 10b is a different from the preceding figures ultrasonic transducer according to the invention 35 shown according to another preferred embodiment. For a better overview, the same reference numerals as above are used with regard to corresponding features. In the ultrasonic transducer 35 is in the 9 and 10 a bonding tool 5 used and therein (see also 10a . 10b ) by means of a clamping screw 8th clamped. The ultrasound transducer 35 includes a transducer body 15 That apart from a bore 7 for receiving the bonding tool 5 and a threaded hole for screwing the clamping screw 8th as a rectangular cuboid made of solid material is. In the example shown, the ultrasonic transducer has 35 a total of four vibra- tion excitation elements 55 , which are each a plate-shaped piezoelectric element 38 is. Of these are two piezo elements 38 , which lie one behind the other with respect to the direction of the tool longitudinal axis W, on the one side or on the same surface 39 of the transducer body 15 glued flat, which is the bonding tool 5 facing piezoelectric element 38 an opening for the clamping screw 8th having. On the opposite, to the surface 39 parallel surface 40 are projection-aligned with the two aforementioned piezo elements two further piezo elements 38 glued. In this respect, the transducer body comprises 15 in the example of 9 and 10 only one piezo element carrier 16 , 10b shows schematically simplified that the ultrasonic transducer 35 with attached bonding tool 5 has a vibration mode whose waveform in the mounting point 56 of the bonding tool 5 at which the clamping takes place, causes a rotationally oscillating movement about an imaginary or geometric axis of rotation A, through the vibration node at the level of the mounting point 56 perpendicular to the plane of 10b runs. In this respect, an imaginary or geometric reference plane E in also spanned by the tool longitudinal axis W (ie the longitudinal direction of the bonding tool) and the said axis of rotation A extends 10b perpendicular to the drawing plane. It becomes clear that all four vibration excitation elements 55 (ie all piezo elements 38 ) from the reference plane E laterally or in the plane of extension of the Peizoelemente 38 are arranged vertically spaced. To these four piezo elements 38 shows 10a the respective polarization directions P. On the left side in the viewing direction has the upper piezoelectric element 38 one from the surface 39 pointing away polarization direction P, while the lower piezoelectric element 38 one to the surface 39 has pointing polarization direction P. On the opposite side, the upper piezoelectric element has one to the surface 40 pointing polarization direction P and the lower piezo element 38 one from the surface 40 pointing away polarization direction P on. Will the Schwingungserregungsele mentträger 57 , In which it is in the example due to the use of piezoelectric elements as vibration excitation elements to the piezoelectric element carrier 16 is grounded, for example, and to the free surfaces of the piezoelectric elements 38 applied to each other in-phase AC voltage, this leads within the levels of the piezo elements 38 and thus also or even predominantly parallel to the imaginary extension of the tool longitudinal axis to temporally alternating strains and compressions. In the 10b Registered arrows illustrate that the two piezo elements 38 , whose polarization direction P to the transducer body 15 indicates a mutually in-phase change in length (in the illustrated time just an elongation) and that the two remaining piezoelectric elements 38 , whose polarization direction respectively from the transducer body 15 points away, also a pair of the same, but to the two above-mentioned piezoelectric elements 38 opposite change in length (for the time shown so just a compression experienced). Thus experienced each two piezo elements 38 , which are opposite to each other with respect to the reference plane E aligned, mutually opposite changes in length. Also two piezo elements each 38 that are on the same surface ( 39 or 40 ) are glued to each other in each case opposite changes in length. In the 9 and 10a . 10b is the voltage or power supply of the piezo elements 38 not shown. For example, but as already stated, the transducer body could be grounded (or another potential applied thereto) and to the free surface area of all the piezoelectric elements 38 , For example, by means of electrically conductive connection with each other, a mutually in-phase AC voltage can be applied.

At the transducer body 15 it is a cuboid basic body made of metallic material whose longest side is vertical, that extends in the direction of the extension of the tool longitudinal axis W. Due to the opposite as previously described changes in length of the piezoelectric elements 38 performs the Transducer body 15 Bending vibrations, wherein the cross section in "bending direction", ie in respect to the viewing direction of 10a . 10b lateral or horizontal direction, which has the least extension. Preferably, and in the example shown, the transducer body vibrates as in FIG 10b shown in its second bending eigenmode. For two free edges, this eigenmode has three nodes, of which the lowest is at the height of the mounting point 56 of the bonding tool 5 located. In the example below are the length of the bonding tool 5 distributed three more, also with 58 designated vibration node. Also the bonding tool 5 thus performs bending modes. The bonding tool 5 and the transducer body 15 are tuned by their geometrical dimensions and the material properties so that they each have approximately the same eigenfrequencies on their own (for the named eigenmodes). If these two parts are joined together, the overall system also shows a corresponding natural frequency. It is preferred (as shown) that the upper node vibration 58 of the bonding tool 5 and the lower node of vibration 58 of the transducer body 15 locally on a common point. At this point or at this level is also the clamping of the bonding tool 5 by means of the clamping screw 8th (in the example a grub screw). In this sense, the bonding tool sets 5 the flexural vibration of the transducer body 15 seamlessly on. To the bonding tool 5 to be able to clamp, there is the blind hole-shaped bore 7 for the bonding tool 5 not exactly centered in the bending plane of the transducer body 15 However, a slight offset hardly affects the vibration behavior. Alternatively, however, a bearing of the bonding tool would ideally be possible in the middle in the bending plane. The bonding tool sits in the plane orthogonal to the bending plane 5 in the example ideally in the middle.

In the embodiment (cf. 9 ) can be the storage of the ultrasonic transducer 35 or its mounting to a bonding head by means of two lateral connection devices 59 take place, which are opposite to each other at the two to the surfaces 39 . 40 orthogonal lateral surfaces of the transducer body 15 are attached. These each have a connection bore 60 , in or through which can not be performed with mounting screws shown for mounting to the bonding head. Each connection device is located above and below the connection bore 60 each a solid-state joint 61 (ie there are four total solid joints in total 61 ), which are regions of smaller cross-section to decouple the bending vibrations. Preferably, these bending zones lie exactly at the height of the upper and middle vibration nodes 58 of the transducer body 15 (see. 10b ). Here, the basic body performs a quasi-pure rotation, whereby the bending joints act ideally and can decouple the vibration system from its environment in this way. Alternatively, variants are possible in which the solid-state joints at the level of the upper and lower vibration node 58 of the transducer body 15 or at the level of the middle and the lower vibrational node 58 of the transducer body 15 are located. Above and below the solid joints 61 There are connections of the connection devices 59 with the transducer body 15 , Preferably, the connection device 59 with the transducer body 15 executed in one piece or integrally, ie the storage and the body are designed in one piece, but it would also be a different design conceivable.

Also in the in the 9 and 10 In the embodiment shown, the ultrasonic vibrations are generated by thin piezoplates. Again, the direction of oscillation orthogonal to the polarization direction P and the electric field is used. As already explained above, in order to ideally excite the vibration mode of the main body (especially the second bending mode), a total of four piezo elements are used 38 used, with each diago nal opposing elements in a similar manner temporally syn chron stretch or stretch. Modifications are possible, for example, in that either on the two on the surface 39 glued piezo elements 38 or on the two on the surface 40 glued piezo elements 38 is waived. Even with the resulting embodiment of the transducer body would 15 still excited to his second bending mode. Another modification would be possible by way of example with reference to FIGS 10a . 10b either on the two upper or on the two lower piezo elements 38 is waived. In such an arrangement, the transducer body would 15 excited to its first bending mode, whereby here, with a suitable vote, an oscillating torque introduction into the bonding tool 5 he follows. Analogously, embodiments are possible in which, starting from the 9 and 10 on every surface 39 . 40 one or more additional, in extension of the tool longitudinal direction W consecutive piezo elements 38 are provided to thereby the Transducererkörper 15 to encourage higher bending modes.

All disclosed features are (for itself) essential to the invention. In the disclosure of the application will hereby also the disclosure content of the associated / attached priority documents (Copy of the advance notice) fully included, too for the purpose, features of these documents in claims present Registration with.

Claims (33)

Bonding device, in particular for the production of bond connections between electrical conductors made of wire or strip material and contact points of substrates such as in particular of electrical circuits, wherein the bonding device around a, in particular vertical, geometric axis of rotation (D) rotatable bondhead ( 2 ), to which a bonding tool ( 5 ) and an ultrasonic transducer ( 35 ) for ultrasonic vibration excitation of the bonding tool ( 5 ) are provided, characterized in that the main extension direction ( 36 ) of the ultrasound transducer ( 35 ) and / or its direction of extension in the direction of the axis of the minimum mass moment of inertia parallel to the geometric axis of rotation (D) of the bonding head ( 2 ). Ultrasonic transducer, in particular for a bonding device for ultrasonic vibration excitation of the bonding tool of the bonding device, wherein the ultrasonic transducer comprises at least one vibration exciter and the vibration exciter comprises at least one piezoelectric element and wherein an ultrasonic energy source, in particular a voltage source for applying electrical alternating voltage to the piezoelectric element is provided by in that the ultrasonic energy source, in particular the voltage source ( 42 ), in particular their frequency, adapted thereto or is adjustable so that in operation, in particular when applying the AC voltage, the main deformation direction of the vibration generator ( 37 ) and / or the main deformation direction of the piezo element ( 38 ) transversely to the polarization direction (P) of the piezoelectric element ( 38 ) Bonding device, in particular for producing bonds between electrical conductors made of wire or strip material and contact points of substrates, in particular of electrical circuits, wherein the bonding device ( 1 ) a bondhead ( 2 ), which is a bonding tool ( 5 ) and an ultrasonic transducer ( 35 ) according to the preceding claim. Ultrasonic transducer for ultrasonic vibrational excitation of a bonding tool, wherein the ultrasound transducer has at least two vibration exciters spaced apart from one another and wherein at least one ultrasound energy source is provided for supplying the vibration exciters, in particular at least one voltage source for applying alternating electrical voltage to the vibration exciters, characterized that one or more ultrasonic energy sources, in particular the voltage source ( 42 ) or the voltage sources, in particular the frequency and / or the phase position, in such a way to the ultrasonic transducer ( 35 ) and the bonding tool ( 5 ) is tuned or tunable, that during operation the main directions of deformation of the two vibration exciters ( 37 ) parallel to each other or substantially parallel and the time-varying deformations of the two vibration exciters phase-shifted in the main deformation directions to each other, in particular phase-shifted by half a period, result. Bonding device, in particular for the production of Bond connections between electrical conductors made of wire or strip material and contact points of substrates such as in particular of electrical Circuits, wherein the bonding device has a bonding head, on which a bonding tool received in a tool holder, which is in particular a wedge, is provided, characterized in that on the bonding head of the bonding device an ultrasonic transducer according to claim 4 is provided. Bonding device according to one or more of the preceding claims or in particular according thereto, characterized in that the geo metric longitudinal axis of symmetry (S) of the ultrasonic transducer ( 35 ) parallel to the geometric axis of rotation (D) of the bonding head ( 2 ), in particular on the axis of rotation (D) or at a small distance therefrom, and / or parallel to the longitudinal center line (W) of the bonding tool ( 5 ), in particular on the longitudinal center line (W) or at a small distance therefrom. Bonding device according to one or more of the preceding claims or in particular according thereto, characterized in that the ultrasonic transducer ( 35 ) at least one vibration generator ( 37 ) and each vibration exciter ( 37 ) at least one piezoelectric element ( 38 ), each piezo element ( 38 ) a main extension direction ( 41 ), which are parallel to the geometric axis of rotation (D) of the bond head ( 2 ). Bonding device according to one or more of the preceding claims or in particular according thereto, characterized in that the ultrasonic energy source, in particular the voltage source ( 42 ), in particular the voltage frequency thereof, is adapted or adjustable so that, when the alternating voltage is applied, the main deformation direction of the vibration exciter ( 37 ) and / or the piezo element ( 38 ) at least substantially in the main extension direction ( 41 ) of the piezo element ( 38 ). Bonding device according to one or more of the preceding claims or in particular according thereto, characterized in that the design of the means by means of the ultrasonic transducer ( 35 ) to be excited to vibrate components of the bonding head ( 2 ) and the AC voltage, in particular their frequency, are coordinated or tunable to each other such that the pivot point (P) of the tool holder ( 6 ) positionally with a vibration node of the bonding tool ( 5 ) coincides. Bonding device according to one or more of the preceding claims or in particular according thereto, characterized in that the frequency of the ultrasonic energy source, in particular the voltage frequency at the voltage source, is preselected or is adjustable so that it corresponds to a resonant frequency, in particular the lowest resonant frequency, in case of concerns Alternating voltage oscillating assembly, the ultrasonic transducer ( 35 ), the tool holder ( 6 ) and the tool ( 5 ), at least approximately corresponds. Bonding device according to one or more of the preceding claims or in particular according thereto, characterized in that one or more piezo elements ( 38 ) in each case has or have the shape of a rectangular-edged disk, the polarization direction (P) of each piezoelectric element ( 38 ) is oriented transversely to its disc plane. Bonding device according to one or more of the preceding claims or in particular according thereto, characterized in that the ultrasonic transducer ( 35 ) at least two mutually parallel vibration exciter ( 37 ), each vibration generator ( 37 ) a piezoelectric element carrier ( 16 ) and two similar piezo elements ( 38 ), the two surfaces facing away from each other opposite and parallel to each other surfaces ( 39 . 40 ) of the piezoelectric element carrier ( 16 ), in particular glued to it surface, are. Bonding device according to one or more of the preceding claims or in particular according thereto, characterized in that the polarization direction (P) of piezo elements ( 38 ), which are part of the same vibrator ( 37 ) are directionally opposed to each other. Bonding device according to one or more of the preceding claims or in particular according thereto, characterized in that the polarization directions (P) of the two piezo elements ( 38 ), which on one of the two Piezoelementträger ( 16 ) are applied, directionally from the piezoelectric element carrier ( 16 ) are directed away and that the polarization directions (P) of the two piezo elements ( 38 ), on the other of the two Piezoelementträger ( 16 ) are applied, directionally to the piezoelectric element carrier ( 16 ) are executed. Bonding device according to one or more of the preceding claims or in particular according thereto, characterized in that the piezoelectric elements ( 38 ) on its free, the piezoelectric element carrier ( 16 ) facing away from the surface of the ultrasonic energy source, in particular to the voltage source ( 42 ), and that the piezoelectric element carriers ( 16 ) are grounded. Bonding device according to one or more of the preceding claims or in particular according thereto, characterized in that the ultrasonic energy source, in particular the voltage source ( 42 ) to the provision of a mutually in phase electrical alternating voltage for all piezo elements ( 38 ), in particular in that the connecting cables ( 43 . 45 ) of all piezo elements ( 38 ) are connected in parallel to each other. Bonding device according to one or more of the preceding claims or in particular according thereto, characterized in that the bonding tool has a geometric tool longitudinal axis (W) extending parallel to the main direction of extension ( 41 ) of the piezo elements ( 38 ) and / or along the geometric axis of rotation (D) of the bonding head ( 2 ). Bonding device according to one or more of the preceding claims or in particular according thereto, characterized in that the two piezoelectric element carriers ( 16 ) Components of a one-piece transducer body ( 15 ), on which in particular also the tool holder ( 6 ) is integrally mounted. Bonding device according to one or more of the preceding claims or in particular according thereto, characterized in that the transducer body ( 15 ) a holding fork ( 19 ), whose retaining arms ( 20 ) at its longitudinal end ( 21 ) on each a piezoelectric element carrier ( 16 ) attack in the longitudinal center region. Ultrasonic transducer, comprising at least one transducer body ( 15 ) and at least one vibration excitation element ( 55 ) connected to the transducer body ( 15 ) in a for transmitting the vibrations generated by him to the Transducererkörper ( 15 ), characterized in that the ultrasonic transducer ( 35 ), in particular with at the tool holder ( 6 ) mounted bonding tool ( 5 ), a vibration mode whose waveform at the mounting point ( 56 ) of the bonding tool ( 5 ) causes a rotationally oscillating movement about at least one axis of rotation (A). Ultrasonic transducer according to one or more of the preceding claims or in particular according thereto, characterized in that the vibration excitation element ( 55 ) on the transducer body ( 15 ) is fixed non-positively and / or positively and / or cohesively. Ultrasonic transducer according to one or more of the preceding claims or in particular according thereto, characterized in that the oscillatory rotational movement about at least one to the longitudinal axis (W) of the bonding tool ( 5 ) is oriented perpendicular or at least substantially vertical geometric axis of rotation (A). Ultrasonic transducer according to one or more of the preceding claims or in particular according thereto, characterized in that by the geometric longitudinal axis (W) of the bonding tool ( 5 ) or a geometric line parallel thereto and by the said axis of rotation (A) a geometric reference plane (E) is clamped, that the at least one vibration excitation element ( 55 ) is laterally spaced from the reference plane (E) and that the vibration excitation element ( 55 ) on the transducer body ( 15 ) applied force in or substantially in the direction of the longitudinal axis (W) of the bonding tool ( 5 ) acts. Ultrasonic transducer according to one or more of the preceding claims or in particular according thereto, characterized in that at least two vibration excitation elements laterally spaced from the reference plane (E) ( 55 ) are present, which are arranged opposite to each other with respect to the reference plane (E). Ultrasonic transducer according to one or more of the preceding claims or in particular according thereto, characterized in that one or more energy sources, in particular one or more voltage sources, are provided for supplying energy to the vibration excitation elements ( 55 ), which in such a way with the vibration excitation elements ( 55 ), that these, in particular to each other on the same or on different sides of the reference plane (E) arranged, vibration excitation elements ( 55 ) exert an oscillation mutually phase-shifted by 180 °. Ultrasonic transducer according to one or more of the preceding claims or in particular according thereto, characterized in that on each side of the reference plane (E) at least two vibration excitation elements ( 55 ) are arranged, wherein on both sides of the reference plane (E) arranged vibration excitation elements ( 55 ) are opposed to each other in pairs, wherein on the same side of the reference plane (E) mutually adjacent vibration excitation elements ( 55 ) are connected to the one or more energy sources in such a way that they exert vibrations which are phase-shifted relative to one another by 180 °, and in which vibration excitation elements which are opposite each other in pairs with respect to the reference plane (E) 55 ) are so connected to the one or more energy sources that they exert mutually 180 ° out of phase oscillations. Ultrasonic transducer according to one or more of the preceding claims or in particular according thereto, characterized in that in each case at least two vibration excitation elements arranged on the same side of the reference plane (E) ( 55 ) in the direction of the geometric longitudinal axis (W) of the bonding tool ( 5 ) are arranged one behind the other. Ultrasonic transducer according to one or more of the preceding claims or in particular according thereto, characterized in that the transducer body ( 15 ) only one vibration excitation element carrier ( 57 ) and that the vibration excitation elements ( 55 ), especially all vibration excitation elements ( 55 ), with the formation of a vibration exciter on two opposing surfaces facing away from each other ( 39 . 40 ) of the vibration excitation element carrier ( 57 ) are arranged, wherein the vibration excitation element carrier ( 57 ) has at least substantially the shape of a rectangular parallelepiped or a rectangular plate. Ultrasonic transducer according to one or more of the preceding claims or in particular according thereto, characterized in that as vibration excitation elements ( 55 ) each at least one piezoelectric element ( 38 ) and that the transducer body ( 15 ) only one, all Piezoelemente carrying piezoelectric element carrier ( 16 ) having at least substantially the shape of a rectangular parallelepiped or a rectangular plate. Method for producing bonded connections, in particular between electrical conductors made of wire or strip material and contact points of substrates, in particular of electrical circuits, comprising the method steps: providing a bonding tool, providing an ultrasonic transducer for ultrasonic vibration excitation of the bonding tool, wherein the ultrasonic transducer comprises at least one vibration exciter and the vibration exciter comprises at least one piezoelectric element, providing an ultrasonic energy source for supplying the piezoelectric element, in particular a voltage source for applying alternating electrical voltage to the piezoelectric element, and vibrational excitation of the bonding tool during the pressing of an electrical conductor to be bonded by means of the bonding tool to a contact point, characterized that for the vibration excitation of the bonding tool ( 5 ) the ultrasonic energy source, in particular the voltage source ( 42 ), in particular the ultrasound frequency thereof, is selected or set such that, during operation, the main geometric deformation line ( 49 ) of the vibration exciter ( 37 ) and / or the main deformation line ( 50 ) of the piezo element ( 38 ) transversely to the polarization direction (P) of the piezoelectric element ( 38 ). Method for producing bonded connections, in particular between electrical conductors made of wire or strip material and contact points of substrates, in particular of electrical circuits, comprising the method steps: providing a bonding tool and an ultrasonic transducer for ultrasonic vibration excitation of the bonding tool, vibration excitation of the bonding tool during the pressing of a bonding electrical conductor by means of the bonding tool on a contact point, characterized in that in the bonding tool ( 5 ) to the vibration excitation of the tool holder ( 6 ) An oscillating torque (M) is initiated, the geometric axis of rotation (A) transverse to the tool longitudinal axis (W). Method according to the preceding claim or in particular according thereto, characterized in that the oscillating torque (M) at the location of a vibration node of the bonding tool ( 5 ) is introduced therein. Method according to one or more of the preceding claims or in particular according thereto, characterized in that a bonding device ( 1 ) is used according to one or more of the preceding claims.